A motion platform system is a device that imparts a translational or a rotary motion or both, to an equipment coupled to a simulator. Usually, such simulators have a moving platform connected to a fixed base. The platform is movable with respect to its base, and has a freedom of motion in all the three axes of a coordinate system, i.e., X, Y, and Z. Specifically, the platform is enabled by an actuating system to undergo any type of motion along or about the three axes.
For example, motion simulators can be employed to provide a virtual helicopter or cockpit environment for trainee pilots. The motion platform in such cases is used to mount an enclosure in a way that the enclosure undergoes various types of motions in sync with the motion of the motion platform. In this way, the moving enclosure gives a person sitting inside the enclosure an apparent feeling of a ride inside an actual helicopter, a space vehicle, etc. On similar lines, the motion simulators are used in amusement parks to give a patron an apparent feeling of riding or flying in virtual space. In such cases, the motion of the enclosure is synchronized with a series of running sequences in a movie that is telecast at a giant screen in front of the patron.
Conventional motion simulators consist of a planar spatial frame connected to the fixed base. The spatial frame is supported on the fixed, grounded base with the help of a number of linear actuators. At least six linear actuators or kinematic legs connect the grounded base to the spatial frame. The connection of each actuator is implemented with the help of movable joints. By virtue of a characteristic of length variation associated with the linear actuators, motion of the spatial frame in all three axes is achieved. Additionally, the spatial frame is enabled to be in motion in accordance with any sort of translational or rotary motion in the three axes.
However, in order to achieve a single degree of freedom associated with the spatial frame, more than one actuator is operated by the motion simulator. Typically, for any sort of movement, all the actuators need to be moved simultaneously with varying velocities. Hence, even if a less degree of freedom is required for a particular movement, all the actuators connected between the spatial frame and the grounded base are operated. Further, in case an end of the spatial frame is lifted so as to accomplish the rotary motion, the total load of the enclosure mounted on the spatial frame is directly on the actuators.
Furthermore, the design of the conventional motion simulators is highly complex. Maintenance and upkeep costs associated with these complex simulators are also high. Moreover, the actuators employed in the conventional motion simulators are of a high power rating, thereby leading to excessive power consumption and an increase in the operating cost.